24. The Prime Minister only two days ago expressed to me the opinion that it ought to be possible to find physical means of absolutely sealing up all escape for submarines from their own ports. The fact that all such methods (nets, mines, obstructions, etc.) inherently involve the added necessity of continuous protection and maintenance by our own Naval forces is seldom understood and appreciated. I finally convinced the Prime Minister of the fallacy of such propositions by describing the situations into which we would be led: namely, that in order to maintain our obstructions we would have to match the forces the enemy brought against them, until finally the majority if not all of our forces would be forced into dangerous areas where they would be subject to continual torpedo and other attack, in fact in a position most favourable to the enemy. 25. Entirely outside of the fact that the enemy does, and always can, force exits, and thereby nullify the close blockade, the weather is a serious added difficulty. The heaviest anchors obtainable have been used for nets, mines, and obstructions, only to have the arduous work of weeks swept away in a few hours of heavy weather. Moorings will not hold. They chafe through. In this respect we could be of great assistance, i.e. in supply of moorings and buoys. 26. The Channel is not now, and never has been, completely sealed against submarine egress, let alone the vaster areas of escape to the north. Submarines have gone under mine-fields, and have succeeded in unknown ways in evading and cutting through nets and obstructions. 27. In addition to submarines, heavy forces are free to raid, and in fact escape through, the Channel at any time when the enemy decides that the necessity or return will justify the risk. Hence the suggestion that two divisions of our fast Dreadnoughts might be based upon Brest, primarily for the resulting moral effect against such possible raids. I was told yesterday by an important Admiralty official that while he thought the chances of raids in, or escape through, the Channel by heavy enemy forces out of reach of the Grand Fleet (North of Scotland) were very remote, nevertheless the possibility existed and was principally thwarted on moral grounds, that is, the uncertainty in his mind of the opposition which would be encountered. He agreed with others, including the First Sea Lord, that the addition of some of our heavy forces to those maintained in southern Channel approaches by the French and British would undoubtedly entirely preclude the possibility of such raids. 28. _Submarine Losses_: